The autumn of 2016 was the warmest ever observed in records going back to 1895 for the 48 contiguous U.S. states, according to data released on Wednesday by NOAA’s National Centers for Environmental Information (NCEI). The nation’s average September-to-November temperature of 57.63°F was a full 1.05°F above the previous autumn record, set way back in 1963, and it was 4.08°F above the 20th-century average (see Figure 1). The record-setting margin of more than ...

With just three years left to go, it’s virtually certain that the 2010s will be warmer than any decade on record, barring a massive volcanic eruption. As greenhouse gases produced by human activity continue to build up in the atmosphere, it’s also a very good bet--again barring a volcanic or geopolitical cataclysm--that the 2020s will be warmer than the 2010s. You wouldn’t know about these perfectly reasonable, science-based inferences if all you had to go by ...

After a markedly mild November marked by thousands of daily record highs and less than 100 record daily lows (more on that in our upcoming monthly roundup), it will feel much more like December across the bulk of the contiguous U.S. over the next couple of weeks. Some locations may see their coldest weather in years as a series of Arctic high pressure cells swing through western Canada and southward across all but the Desert Southwest.

The largest U.S. tornado outbreaks have been spitting out an ever-increasing number of twisters, according to a study published Thursday in the journal Science. The new paper, led by Michael Tippett (Columbia University), reinforces prior work showing that U.S. twisters are increasingly concentrated in big outbreaks, with the quiet periods becoming even quieter. Tippett and colleagues also threw in a noteworthy curve ball. It appears the growing number of tornadoes ...

After three relatively quiet seasons, the hurricane-generating waters of the North Atlantic, Gulf of Mexico, and Caribbean returned in 2016 to the busy production schedule they’ve maintained in most years since the mid-1990s. Assisted by the switch from a record-strong El Niño to a borderline La Niña, which reduced vertical wind shear, the 2016 season ended up above the long-term average for all of the most commonly tracked indices, with the largest number of hu...